Electrochemical polymerization of palladium (II) and free base 5,10,15,20-tetrakis(4-N,N-diphenylaminophenyl)porphyrins: Its applications as electrochromic and photoelectric materials

Free base and Pd(II) 5,10,15,20-tetrakis(4-N,N-diphenylaminophenyl)porphyrin form conductive, stable and reproducible electropolymer films. The combined electrochemical and spectroscopic studies show that the electropolymerization mechanism involves the dimerization of triphenylamine units, conducting the formation of a tridimensional structure where porphyrin cores are in a perpendicular fashion that avoids aggregation. Switching between the polymer neutral and oxidized states produced color changes which can be observed by the naked eye, and the films showed to be efficient in the generation of photoelectric effects. All these characteristics make the polymers as promising materials for application in optoelectronic devices. (C) 2009 Elsevier Ltd. All rights reserved.